Tread surface and periphery of a footwear unit sole



FIG. 1 is a bottom plan view of a tread surface and periphery of a footwear unit sole showing my new design;

FIG. 2 is a right side elevational view;

FIG. 3 is a left side elevational view;

FIG. 4 is a front edge elevational view; and,

FIG. 5 is a rear edge elevational view. 

The ornamental design for a tread surface and periphery of a footwear unit sole, as shown and described. 